Cooling and suction device of an installation comprising a furnace having at one side a burner producing a flow of hot gases and at the other side a distributor of material to be boiled



May 6, 1969 DIQNISOTTI ETAL 3,442,496

COOLING AND sUCTIoN DEVICE OF AN INSTALLATION COMPRISING A FURNACE HAVING AT ONE sIDE A BURNER PRODUCING A FLOW OF HOT GAMES AND AT THE OTHER SIDE A DISTRIBUTOR OF MATERIAL To BE BOILED Filed July 6, 1967 United States Patent Oifice 3,442,495 Patented May 6, 1969 9,82 Int. Cl. F27b 7/38; F27d 17/00 US. Cl. 263-32 3 Claims ABSTRACT OF THE DISCLOSURE A cooling and suction device of an installation comprising a furnace having at one side a burner producing a flow of hot gases and at the other side a distributor means of material to be boiled, which comprises means for feeding hot gases and material in counter current relative to each other, the gases, being cooled during normal operation, being in contact with the material to be boiled. An evacuation chimney leads to free air and purifying means are operatively connected with the evacuation chimney. Auxiliary means are arranged for feeding cold air into the flow of hot gases slightly prior to the passage of the latter into the purifying means, and also means are provided for cooling the flow of hot gases.

The present invention relates to a cooling and suction device of an installation comprising a furnace having on one side a burner producing a flow of hot gases and on the other side a distributor of material to be boiled.

The gases and the material flow through the furnace in opposite direction and the gases, cooled in normal operation of the installation, are in contact with the material to be boiled, and traverse the same, and upon emerging from the furnace, purifier means are provided before they reach the evacuation chimney to the free air.

Installations of this type are notably used for the manufacture of cement in a dry or moist manner. In normal operation the gases emerging at one side of the furnace are sufliciently cooled at the point of contact of the material to be boiled in order to introduce the same without inconvenience into conventional purifiers (electric filters, dust removing devices, and others). On the other hand, in case of starting up or in case of stopping the installation, also in case the supply of the material to be boiled is interrupted, the gases emerge at the side of the furnace at a temperature not much elevated'and are evacuated in the known installations through a chimney, called allumage, without passing through the purifier means. This chimney having natural draft permits the escape of the gases containing dust into the atmosphere.

It is one object of the present invention to provide a cooling and suction device which avoids this inconvenience.

It is another object of the present invention to provide a cooling and suction device, wherein auxiliary means are included which permit the introduction of cold air into the flow of hot gases in order to cool this flow slightly prior to its passage into the purifier means, and also cooling means for cooling the flow of hot gases.

One can thus restore the temperature of this flow to an acceptable temperature for the purifier means, so that the supply of the material to be boiled is not yet collected.

In a preferred embodiment, the auxiliary means comprise a conduit forming a by-pass around the distributor means and include the application of fresh air. In another embodiment means are provided for cooling the flow of hot gases by a cooling fluid.

With these and other objects in view which will become apparent in the following detailed description, the present invention will be clearly understood in connection with the accompanying drawings, in which:

FIGURE 1 is a schematic elevation of an installation for the production of cement manufactured in a dry manner;

FIG. 2 is a fragmentary elevation of the installation disclosed in FIG. 1, at an enlarged scale; and

FIG. 3 is a schematic elevation of another embodiment of the installation for the boiling of cement manufacture in a moist manner.

Referring now to the drawings, and in particular to FIG. 1, the installation for the boiling of cement manufactured in its dry state comprises a rotary furnace 1 having at one end a burner 2 and at the other end a preheater 3, a movable grate consisting of a distributor 4 supplying the furnace in a continuous manner. The unpurified cement flour descends along the furnace in a counter current movement to the flow of the hot gases produced by the burner 2. Once transformed into clinkers, it emerges from the furnace through a cooler 5. The flow of the gases emerges from the preheater 3 through a conduit 6 and across an electric filter 7 prior to being removed into the free air by means of a ventilator 8 which communicates with a chimney 9.

A conduit 11 constitutes a by-pass about the preheater 3. This conduit 11 consists of a vertical chimney 12 opening into a container 13 of larger cross-section by means of a tubular member 14. The container 513 comprises at its base, on the one hand, a feed 15 of lateral air and, on the other hand, a tubular lateral exit '16 connected with a centriguge separate 17 by means of a heat exchanger conduit 18. A conduit 19 leads into a butterfly valve 20 connecting the exit of the separator 17 with the conduit -6.

A cut-oil 21, vertically movable in the container 13, has a head portion 21a placed opposite the tube 14 and an inner cylinder 21b capable of obscuring the openings of the air entrance 15 and of the air exits 16.

In the elevated position of the cut-off 21, shown in the left portion of the container in FIG. 2, the tubular mem ber 14 and the openings 15 and 16 are open, while in the lowered position, shown at the right half of the container 14, this tube 14 and the openings 15 and 16 are closed. The cut-off 21, the position of which is controlled by a mechanically operating mechanism (not shown), can also be placed in intermediate positions.

The conduit 18, the separator 17, and one portion of the conduit 19 are surrounded by a jacket 22 which receives the circulation of cooling water. In order to increase the exchange surfaces, the inner wall of the conduit .18 includes longitudinal ribs 181:.

During normal operation, the gases Which have a temperature of about 1500 C. in the clinkering zone, are sufliciently cooled upon contact with the cement flour in order to emerge from the preheater -3 at a temperature of to 200 C., which is compatible with their passage in the electric filter 7. The cut-off 21 is closed in a manner that they by-pass conduit 11 is not in operation and that the disposable heat is best utilized.

On the other hand, if the supply of flour is interrupted, the gases arrive at one side of the furnace at an elevated temperature of the order of 800 to 1000 C. approximately. One opens then the cut-off 21 and the valve 20, in order to put into operation the by-pass conduit 11.

With certain types of preheaters, which are for instance known under the trade name Lepol, the putting into operation of the by-pass 11 is also necessary in view of a stoppage of the distributor grate, which does not permit a satisfactory passage of the gases, as well as their movement.

Once the conduit 11 is opened the hot gases, rising in the tube 12, discharge into the container 13 from which they are exhausted by means of the ventilator 8 by means of the separator 17. Due to the low pressure established in the container .13, fresh air, penetrating during the air entrance 15, is mixed with the hot gases.

The cooling, due to the circulation of the water in the jacket 22 contributes also to cool the gases, the temperature of which is lowered to about 150 C., which temperature is compatible with a good functioning of the electric filter 7.

The gases are then filtered prior to their exit, which permits to prevent any pollution of the air.

The by-pass 11 can also be utilized momentarily in case of a malfunction of the preheater and one recognizes that the tube 12 can also serve, in case of necessity, for a direct evacuation of the gases through the opening 15, if the valve is maintained closed, while the cut-off 21 is open.

In the installation disclosed in FIG. 3, for the container for the boiling of the cement manufactured in a moist manner, a furnace does not include a preheating section of a grate, rather terminates, by means of a channel of a distributor 31, into a suction chamber 32.

A by-pass conduit 33 operated in the same manner as the conduit 11 of the previous embodiment is arranged between the lower portion 34 of the furnace and the adjacent portion 35 of the chamber 32, a damper 36 and all other means for cutting-01f, which permit to insulate the furnace 30 from the suction chamber 32, as soon as the by-pass conduit is put into operation.

The presence of the disclosed installations of the conduit forming a by-pass 1'1 and 33 have the following advantages:

Dust and other impurities are retained equally during the phases of operation and stand still by means of the filters or purifiers during normal operation.

The by-pass conduit can be utilized occasionally for the discharge into free air.

The introduction of air into the fiow permits a sufficient cooling of the latter without extensive consummation of water.

The introduction of air does not necessitate a supplemental ventilator.

The by-pass conduit is easily installed in the existing installations between the supply tube and the suction conduit of the filter.

Though the by-pass conduits 11 and 33 are surrounded by a jacket through which cooling Water circulates, a reduction of the temperature of the gases necessitates sometimes the admission of a very large quatity of fresh air, which is then ditficult to circulate across the purifier by the normal suction means.

For this reason in the different shown arrangements, it is possible to install in the by-pass conduits 11 and 33 water distributor means provided to introduce, with a predetermined quantity, water or steam in the flow of the hot gases.

In a preferred embodiment, these preferred water distributor means comprise for example, a supply arrangement which consists of a tank 23 having a constant water level supplied thereto under predetermined pressure, a cooling means, e.g., a cooling coil 24 placed inside of the by-pass conduits 11 and 33 and the exit 24a of which terminates in the mentioned conduit. The water fed to this cooling coil, which functions like a single tubed hot water boiler, is heated progressively and discharges in form of steam into the flow of the hot gases. A control means 24b controls the waterfeed such that the total water supply is vaporized in the cooling coil 24 prior to the discharge into the conduit.

In one preferred embodiment the' supply of this cooling coil is controlled such, that the total water is vaporized in the latter, so that steam fed to the gases is superheated steam.

The introduction of Water contributes to a very efiicient cooling of the gases, due to the necessary heat of vaporization.

In addition, the humidification of the gases is favorable for a good functioning of the electrostatic purifier employed generally in order to retain the dust.

In the variations, the cooling coil can be replaced by other forms of evaporators. One can equally provide as direct grinding means a water jet for cooling in the bypass conduit.

The present invention is not limited to the installation for the preparation of cement, but can be applied equally to furnaces of other types.

While we have disclosed several embodiments of the present invention it is to be understood that these embodiments are given be example only and not in a limiting sense, the scope of the present invention being determined by the objects and the claims.

We claim:

1. A cooling and suction device of an installation comprising a furnace having at one side a burner producing a flow of hot gases and at the other side a distributor means of material to be boiled, comprising means for feeding said hot gases and said material in counter current relative to each other, said gases, being cooled during normal operation, being in contact with said material to be boiled,

an evacuation chimney leading to free air,

purifying means operatively connected with said evacuation chimney,

auxiliary means for feeding cold air into said flow of hot gases slightly prior to the passage of the latter into said purifying means,

means for cooling said flow,

said auxiliary means comprises a by-pass conduit constituting a by-pass avoiding said distributor means, means for feeding fresh air into said conduit,

said by-pass conduit includes a vertical tubular portion terminating in a container having an end part of larger cross section,

said container having at its base a lateral air entrance means and a lateral tubular exit portion operatively connected with said purifying means, and

a cut-off means axially movable in said container and including a cover capable of covering at least partially air openings and said tubular exit portion.

2. A cooling and suction device of an installation comprising a furnace having at one side a burner producting a flow of hot gases and at the other side a distributor means of material to be boiled, comprising means for feeding said hot gases and said material in counter current relative to each other, said gases, being cooled during normal operation, being in contact with said material to be boiled,

an evacuation chimney leading to free air,

purifying means operatively connected with said evacuation chimney,

auxiliary means for feeding cold air into said flow of hot gases slightly prior to the passage of the latter into said purifying means,

means for cooling said flow,

said auxiliary means comprises a by-pass conduit constituting a by-pass avoiding said distributor means, means for feeding fresh air into said conduit,

said by-pass conduit includes heat exchanger means for cooling by means of a cooling fluid,

said by-pass conduit includes a vertical tubular portion terminating in a container,

said heat exchanger means includes a heat exchanger conduit disposed below said container,

said heat exchanger conduit has inner ribs, and

a jacket surrounding said heal exchanger conduit for circulation of water.

3. A cooling and suction device of an installation comprising a furnace having at one side a burner producing a fiow of hot gases and at the other side a distributor means of material to be boiled, comprising means for feeding said hot gases and said material in counter current relative to each other, said gases, being cooled during normal operation, being in contact with said material to be boiled,

an evacuation chimney leading to free air,

purifying means operatively connected with said evacuation chimney,

auxiliary means for feeding cold air into said flow of hot gases slightly prior to the passage of the latter into said purifying means,

means for cooling said flow,

said auxiliarymeans comprises a by-pass conduit constituting a by-pass avoiding said distributor means, means for feeding fresh air into said conduit,

said by-pass conduit comprises water distributing means, in order to feed predetermined quantities of water and steam, respectively, into said gases,

cooling means disposed in said by-pass conduit and including an exit communicating with said by-pass conduit,

said water distributor means communicating with said cooling means and feeding said water into the latter,

said Water in said cooling means being heated by said gases in said cooling means and discharging from said exit into said by-pass conduit, and

means for controlling the water feed such that the total water supply is vaporized in said cooling means prior to the discharge into said by-pass conduit.

References Cited UNITED STATES PATENTS 1,596,509 8/1926 Pike 263--32 2,157,321 5/1939 Bussmeyer 26353 X 2,659,449 11/1953 Kaiser et al 26353 X 3,317,201 5/1967 Muller et a1. 26332 3,365,521 1/1968 Brachthauser 26353 JOHN J. CAMBY, Primary Examiner. 

